Authorities have arrested Dylann Storm Roof, the suspected gunman in a terrorist attack at a black South Carolina church.

The white supremacist was captured during a traffic stop in Shelby, North Carolina — about 30 miles west of Charlotte.

Police were tipped off by a concerned motorist who spotted a suspicious vehicle.

Descriptions and photos of Roof and his vehicle, which displayed a distinctive Confederate States of America license plate on the front bumper, were circulated widely in the hours between the massacre and his arrest about 11 a.m.

Authorities said Roof cooperated with the officer who stopped him.

He is suspected of killing nine people at a Charleston church Wednesday night, and police do not believe any other suspects were involved.